G. Doeksen & Zonen, Terschelling

N.V Scheepvaartmaatschappij G. Doeksen & Zonen, Terschelling - but
Doeksen was one of the great Rotterdam harbour-barons
Houseflag: white with a yellow St. Andrew's cross; in the center a
red circle, within which a black "D".
Source: houseflagchart attached to the magazine "De Blauwe Wimpel",
April 1956.
Jarig Bakker, 18 Oct 2003

Other sources disagree with this flag. The company itself originated
1916 as N.V. Scheepvaart Maatschappij G. Doeksen & Zonen becoming shown
as N.V. Scheepvaart-en Bergings Maatschappij G. Doeksen & Zonen in
the early 1960s and continues under this name as the registered ship owner
coming under the umbrella of B.V. Rederij G. Doeksen en Zonen together
with associate B.V. Terschellinger Stoomboot Maatschappij. Op de Lange
Deining by Bovens c.later 1950s shows the central portion being a white
circle within a red ring which has white panels at the main compass points
and on the white a blue “D” [see D216 attached]. This format is agreed
to by Wyt’s Digest 1960 and Brown 1995 but they also show a rope loosely
encircling the ring and joining it at the white panel points and with the
rope passing behind the saltire [see D87 attached which is based on Brown
and shows a partial outlining of the saltire which probably means nothing
and merely confuses the viewer).
Neale Rosanoski, 7 Jan 2004